Molding apparatus



Allg. 15, 1933. J' w LOWELL 1,922,168

MOLDING APPARATUS Filed May 9,` 1952 :s sheets-sheet 1 Aug. 15, 1,933.J. w. LOWELL 1,922,168

MOLD I NG- APPARATUS Filed May 9, 1932 3 Sheets-Sheet 2 May-L i? Aug.15, 1933. J. w. LowELL MOLDING APPARATUS Filed kay 9, 1952 3Sheets-Sheet 3 c vPatented Aug. l5, 1933 i' 1,922,163` MOLDING ArrARATUsichn ll. `Lowell,` Chicago, lIll., assigner to Benedict Stone ProductsCompanmhicago,

Ill., a Corporation of Illinois Application May 9, 1932. Serial No.`610,2,38

9 Claims. (Cl. .Z5-.41)

, i My invention relates to method of and ,appa ratus for making precastconcrete and has particular reference toa method of and means forsuspendinga mold While the concrete therein is packed by vibrationsimparted to the mold to taire the place of tamping. c Y

V,The present application is a continuation in part of my priorapplication Serial No. 394,985, `filed September 25, 1929, for Molds,for which this 1) application is substituted, andthe drawings of thepresent application are transferred from said prior application.

Another and further object oftmy `invention is the provision of amethodof and apparatus for c l5 making concrete, in which molds, supported-,by

flexible suspension means, are used `and vibra tions imparted to thesaid molds` and confined t0 the'rnolds Without being scattered to thesupport means. i

the green concrete in molds hy imparting vihration tothe molds whilesumzorting` the molds in i such manner that the vibrations are confined`to in order that uniform binding of the concrete be secured, orvibrations may be imparted directly to the concrete in the molds.` Inmaking precast formsof concrete the usual 3() green concrete and tampthe concrete `into the `xn`olds`to` secure firm bonding oi the blocksor" slabs or other objects `after the concrete has set.

Many objections have `heen found in `this prac- T35 tice, however,particularly owing tothe inability to uniformly tamp the concrete or`compact it to j suiiicient density. Variousvibratory means have beenused for the tamping or packing of the', green concrete and when suchmethods are used r 40 it has been the common practice tomount the moldsupon rigid-supportssuch as floors, tables, frames or the like. lthabeenextrernely difficult to keep the frames fastened toa floor owingto ,the rapidvihration Whichit is necessary to irri`- part to `themolds, andif the frames, Within which l the molds are mounted, are notsecurely fastened to the i'loor,` they creep over the iloorand will notremain, placed in proper position. lf the tachcd `to them theyaredisagreeaoly noisy in operation, sornuch so, that itis almost impossiblefor Worlinen to operate them, particularly `if number molds are Securedtogether in` one room. and the vibrators are partially neutralized ordeflected so that the molds are not evenly v tilted to various positionsfor the purpose of G Another and further object of myinvention isl amethod of making precast `concrete by packing.

better understood by reference to the accompanypractice has been toi'lll` the molds with Wet or pensionmeans illustrated inLFig. 5.

molds are fastened to a door and vibrators,at-`

` ing a motor`16 mounted thereon, with wheels 16a, 1

suspension means 4for the mold, including a flexible sling, which willpermit the mold'to be forming precast concrete slabs o1' varyingthickness of layers of concrete, and` which also *may be utilized forthe handling ofthe mold in the plant after the concrete has set or afterithas M been packed, and which absorbf the vibrationsso Y el that thevibratory movements are confined to the mold.

Another object of the invention is the provision of an improved modeofmounting electric `vibrators of the type having an eccentric weighton fthe motor shaft so that the rotation of the ec` centric Weight mayinduce vibrations oroscillations of" the entire motor casing withrespect `tol the mold, `these"vibrations being transmitted to l, themold through `a resilient and exible motor 3? hanger which1 is carriedby a support secured to the mold by'clampiiig devices. Another object ofthe invention `is the provision of an improved molding apparatusjwhichis adaptedto utilize more effectively the `vihra- S9 tions which may beinducedby means of a motor having aneccentric Weight on its shaft.

These and other objects `vvill `be moreiully and ing sheetsofzuravvings, `and lnwhich Fig. 1 is a side elevationalvievv0I` a moldernploying my improvedsuspens'ion means; f

Fig, 2 is an end elevational ,vieur of the mold illustrated in Fig.` 1;c n

Fig. 3 isa side elevational view `of a modified "0 form of mold andsuspension means;

Fig. 4 isa topplan view of the mold illustrated in Fig. 3 onthelinefi-ei.;`

Fig. 5 illustrates another modified form of `mold. for making large flat'slab structures; and

Fig. 6 is a ,top'plan` view` of the mold and sus- Referring nowspeciflcallytothe drawings, in which like reference charactersrefer tolikeparts throughout, a rectangular shaped frame 10 is ilf lustatedhavinga pair of shaft-.sil and l2`mounted c thereim upon which rollers13-413. are mounted at eaclrof 'their ends, `and which engage tracks 14,14, which are suitably mounted or supported i. one building structure inany desiredfmanner. ,y The frame 10 may be operated manually or may havean electric motorconnected thereto after theusual fashion of cranes ofthis character.

Mounted upon the frame 10 is a carriage 15V hav- 1 16a on said carriagefor engagement with a pair of tracks 161) mounted in the frame 10, andis capable of longitudinal movement therealong. The motor 16 is directlyconnected to a hoisting reel 17, around which a cable 18 operates. Tothe free end of the cable 18 a clevis 19 is attached, which in turnengages a U-shaped member 20 having a pair of flexible loops 21 and 22mounted thereinand which extend around each end of a frame 23, composedof a pair of parallel extending bars 24, 24 and cross lots 26 and V27having suitable spacers thereon, with a mold being mounted on said frame23.

The flexible loops or straps 21, 22 may be made of leather, rope, steelstrap or steel cable, and they constitute a fiexible form hanger for themold or form 25. The base of the mold or the supporting framework forthemoid constitutes a support, which support is provided with clampingmembers 32 for engaging the form, particularly the flanges of the angleirons 31 carried by the mold and clamping the mold to the supportingframework so that the mold will not move yaround under the influence ofvibration upon its vsupporting framework. The vrelatively long andV'case rubber pads were placed between the bars 24 and the bottom of themold to reduce the amplitude of vibration of the motor and reduce theamount of iiexure of the resilient and flexible bars 24. The bars 24 arepreferably made suffi- Y cien'tly flexible to permit the range ofamplitude of'vibration desired, and the necessity for the rubber padsmay be eliminated by making the bars 24 slightly" thicker forv thelonger spans of forms, but in every case the bars 24 must besufficiently flexible to,v permit vibration of the A,motor with respecttothe form.

A vibrating apparatus 28 is mounted upon the frame 23 by being securedto bars 24, 24 intermediate the ends thereof and preferably centrallylocated with respectfthereto by means of 'U-shaped members 24a.

This vibrating apparatus, ask illustrated, comprises an electricallyoperated4 motor lhaving an unbalanced rotor therein which, whenoperated, is designed to impart a vibratory action to the mold 25. Thisvibars`24 constitute a flexible motor hanger for' brating ,apparatus'maybe'eleotrically or steam operated, or in any manner to impart vibrationto the mold'25, to cause a settling or packing of the green concreteafter itis placed in the mold.

The inherently 4flexible and resilient rods or the motor, the ends ofwhich are connected to the support or framework by means of the clampingmembers 32. Various forms of iiexble motor` hangers may be employed,provided the hanger is so arranged that its flexibility is not greatenough to prevent the transmission of the motor vibrations to the mold,but the flexibility motor hanger bars to the mold may be madeadjustable, and the flexibility or resiliency of the motor hanger bars24 may be adjusted, if desired. The spacing members 36 which connect thebars 24 are preferably adjustably mounted upon the bars 24 forlongitudinal adjustment with respect to the bars so that the clampingmembers 32 may be slid back and forth to bring them into proper positionto clamp the motor hanger on forms of different length or width.

rIhe mold 25 is a rectangular shaped device, open at its top and closedon the sides, ends and bottom, and has its bottom plate extending beyondthe end walls cf the mold, forming projections 29 and 30, upon whichangles 31, 31 rest, these angles also engaging the end walls of the mold25. A pair of L-shaped clamping members 32, 32 are provided, which havea threaded member 34 projecting thereinto, with a crank 35 at the lowerend thereof and a spacing member 36, which engages the under side of thebars 24, 24. By tightening the cranks 35, the mold 25 is clamped tightlyupon the frame 23, so that the mold is firmly held in position andsuspended upon the flexible members 21 and 22.

The motor may consist of an ordinary electric motor rotating at about3690 revolutions per minute and having at one or both of its ends aradially extending arm iixedly secured to the end `of the shaft andprovided with an eccentric 2,3

weight preferably located in the motor casing.

Loops 37, 37 are provided around the fiexible members 21 and 22 adjacentto the member 20, so that if it is desired to tilt the mold 25 sidewisein order to produce a precast piece of concrete which is thicker at oneside than at the other, the mold 25 is thereby tilted to one side sothat the flexible members 21 are slightly longer on one side than on theother and the loops 37 are thereupon slipped up against the member 29 sothat the suspension members 21 and 22 are held proper position so thatthe mold is slightly tilted. If it is desired to incline the mold 25with this form of device so that one end is higher than the other, arope or other Jdexible fastening means is secured to one end and thedevice tied to the side of a building or to the track, as be desired, sothat it is turned around its point of suspension on the member 20.

In Figs. 3 to 6, inclusive, a form of mold suspension means is provided,in which a single mold is suspended from two or more hoisting units.This apparatus is desirable for large sizes of precast stones or slabs,and also permits greater flexibility in the handling of the molds. formof apparatus consists of a pair of frames 3 and 10a, which are mountedupon the tracks 14, 14, which are supported on a building in anysuitable manner. ,The frame lea is'constructed in exactly the samemanner as the frame 10, a detailed description of which has been givenheretofore. Hoisting units 15 and 15a (which are-duplicates of eachother in construction) are mounted upon the frames 19 and 10a and havecables 43 and 41, respectively, connected to the hoisting drums, towhich rings 42, 42 are connected at their lower ends. 1Flexible members43 and 44 are provided, which extend around the mold 25 and the frame 23at each of its ends, and extend through eyelets formed in hooks 45, 45which engage the rings 42, 42. The members 43 and 44 have loops 37, 37thereon which, through friction, hold the members 43' and 44 in adjustedpositions for the purpose of canting the mold if desired.

One

fio

vso

i In this formof device, ifit is desired to tilt` `the moldlongitudinally, one end is raised slightly higher` than the other andthrough the hoisting mechanismthereby tilting `the mold a slight degree.f ,V

In Figs; 5 and 6 adeyice is illustrated for mak- `ing precastslabs oflarge dimension, in which a mold of slightly different form `is shownandin which four hoisting elementsV are employed. The

frames l and` 10c are employed; which are mounted upon the rails 14, 14.The frame l0 has a pair of hoisting carriages l and 15b mount` Aedthereon, each of` these carriages having motors mounted thereornwith`hoisting drums con ,nectedtheretd to whichcables 47'and 4B areconnected. The frame a` has a pair of carriages a and `15o mountedthereon, uponwhich motors and hoisting drums are mounted, to whichcables `49and 50 are connected.

`Two pairs of longitudinallyextending rails 24, 24are provided, eachpair being,T secured togeth er by bolts 26 and 27 at each of their ends,with spacers `mounted on saidbolts. Clamping devcescomprisingclampmembers 32, 32, threaded "members 34 and cranks 35, areprovided,fwhich e each of its corners, to which thecables 47, 48, 49,

and are secured,thereby suspending the mold `from the,hoistingapparatus.Inthis form of deviceeach of` the hoistingrmechanisms is operableindependently of` the other, sothat the mold may be `tilted from side"vto side, or `eitherofthe A ends elevated abovethe other, as may bedesired.,A

The vibrating devices are placed underl the mold preferablysomewherenefar the center oi each `quarter section of the bottomof themold, but

J"in "this respect they may beplaced in various pesi- 'tions` andoperatedV either in synchronisin with each other or independently forimpartingvibration to the mold.

`In operationy of the with green concrete and are thereupon ,secured ltothe `longitudinally extending bars 23 and 24 i and clamped firmly inposition upon these bars.` They are then suspended from the flexiblemembers 21 and 22 andvibration imparted to the mold through the memberZiluntil the `green concrete has been caused to settle in the mold tothe de grecV desired, the mold being held in suspended position whilevibration is `imparted toit. Because the suspension straps are ilegible,the vibration isiniparted onlyto` the inoldjand not to the suspensionmeans, `and thereforethe objection tothe molds in a fixedposition uponafioor is avoided, both with. respect to the creeping of the uponrelatively long lresilient `and fiiexible `metal i rails, rods, bars orstraps secured at each end to the mold supporting frame or to themoldlitsell. The iiexibility of the rails, rods, bars` oie-straps mayalso be dirninishedby placingthern under tension, but ii the motorhanger is properly eproportioned in size and length to provide theproper flexibility and resiliency, `no adjusting devices need be'employed.

The operation ofthe vibrating apparatus is `explained as followswithreference to Figs. 5 and,"

6, for example. The mold 51 is supported upon a framework comprisingthev longitudinally extending frame members 5l and transverselyextending frame members 3l,`the framework being "in turn supported bythe flexible'cables 4'?, 49 at `each ol the four corners. The mold andframework are therefore freeto vibrate under the influence ci thevibrators, whichlare preferably located at vthe points of the greatestamplitude ,of

Vibration onthe hangers 23, 24.V For example,

when only-one. vibrator is employed, it maybe located midway between theends, but when two vibrators are employed on each hanger, they may .belocated one quarter of the length of the for from the end of the form. i'i The vibrators 28 are carried in dependingposition from the relativelylong flexible and resilent Vmetal rails 23, 24, which are securedtogether at their ends by spacing members and provided with the clampingmembers 32. The ends of the motor hanger rails are secured to the form`by the clamping engagement of the clamps 2 with the angle irons 3l thusalso servingto clamp the form to the framework 5l, 31. f Y

, The motor vibrator being provided with a relatively small eccentricWeight, when the eccentric weight is rotated, the inertia of theeccentric weight tends to cause the motor to move in van orbit which isopposite in direction to that ofthe rotation of the eccentric weight,

`The range of movement of the motor withreloo Y spect to the range ofmovement of the eccentric Y weight bears a relation which variesinversely as the masses of the eccentric weight and the motor.

Therefore, the amplitude of vibration of the motor is much less thanthat of the eccentric Weight, but the motor possesses a greater mass andhas the capalnlity` of transmitting its vibration more eilectively tothe mold on account of the greaterl I mass of the motor and consequentgreater intensity of its vibrations.

lf the rmotor were unsecured or freely suspended, it would oscillate ina circular orbit, but

as `the motor is carried by a resilient. and exble,

hanger rail it has a greater freedom of moveu l ment in ,the directionin `which the rail will HEX device,`themolds are lled or bend andhasrelatively little freedom of movement in thedirection of thewlengthof the `rail.

rectional characteristic in a vertical direction,`

and these vibrations are transmitted tothe `mold 25 or 5l through theattachment of the motor hanger to themold at its ends. The amount ofiiexure of the resilient rails 23, 24 depends upon their relativestiffness, and if the rails are made 4too slender or too long for theirthickness, they will liex too much and tend to dissipate the vibrationof the motor without transmittingit to the mold 25, 51. e

" The nio'to'r hanger is therefore preferably pro# portioned in size sothat its lexure ioisuiclcnt `"lIherefore, the resilient and flexiblerail permits` `the motor to vibrate up and down in Figf3ior130 vto givethe motor the amplitude of vibration desired, which is a matter of afraction of an inch.

The vibration of the motor vibrator in a vertical plane, in Fig. 3, forexample, tends to bow the hangers 23, 24 slightly, which has a tendency,to shorten their lengthbetween the points of securement of the hangerson the mold. rlChis tendency toward shortening is, however, resisted bythe supporting framework and by the mold, which tend to tension thehangers as the deflection from a straight line increases. Obviously theinherently resilient and flexible hangers may be made stiffer either byincreasing the tension or by increasing their cross sectional area.

After the setting process has been performed by the vibrating apparatus,the hoisting mechanism is used to convey the precast stone or block ofconcrete to any point desired, where it is removed from the mold or isallowed to set until such time as the mold can be removed from thestone. The mold is readily removable from the longitudinally extendingbars, so that a new mold can be secured upon the bars an the operationrepeated.

The operation of the form supports described in Figs. 3 to 6 inclusiveis substantially the same as that heretofore described, with theexception that these devices allow for the tilting of the molds withrespect to end-to-end operation, or canting of the molds from side toside. In the manufacture of precast blocks of concrete it has become thepractice to form an exceedingly dense close surface on one side of theblock and complete it with a different mix of concrete. It may becomedesirable toy have this layer formed more thickly atV one side of Ytheblock than on the other, so that it is necessary to tilt the mold duringthe operation.

In the making of precast concrete or building stone that has becomeknown in the buildi 1g trade, a surface layer of varying color is alsosometimes used and the balance of the buliding stone completed with anordinary ferm of con-- crete. In applying these thin layers of concretethey are usually applied to the bottom of the mold and the balance ofthe filling material superimposed upon the first layer of material.l Theouter surface of the Vstone is formed usually in a plain surface, whiletheV inner side of the stone may be of varying contour and thickness,which can be secured by tilting or canting the molds, as may lbedesired.

It will thus be observed that I have provided an kimproved moldingapparatus, including an improved mode of resilient support for vibratorson the-mold for increasing the effectiveness of the vibrating apparatus.eccentric weight is clamped iixedly to a relatively heavy and stiffform, relatively small eccenytric weight produces but very little effect:in the form of vibrations transmitted to the form, but when thevibrator is resiliently mounted upon resilient members which arevsufficiently flexible to permit a fiexure of the hanger with respect tothe W hen a vibrator having an without departing from the Aspirit orscope of my invention.

Having thus described my invention, what I claim is new and desire tosecure by Letters Pattent of the United States, is:

l. In an apparatus for vibration of concrete, the combination of anelectric motor provided with an unbalancing weight adapted to be rotatedby the motor shaft, a resilient support for said mot r, clamping memberscarried by the opposite ends of said resilient support and adapted toclamp a concrete form, and flexible means for suspending said concreteform, motor and support whereby said motor is adapted to place saidconcrete form in a state of high frequency vibration.

2. In an apparatus for vibration of concrete, the combination of anelectric motor provided with an unbalancing weight adapted to be rotatedby the motor shaft, a resilient support for said motor, clamping memberscarried by the opposite ends of said resilient support and adapted toclamp a concrete form, and flexible means for suspending said concreteform, motor and support whereby said motor is adapted to place saidconcrete form in a state of high frequency vibration, said flexiblemeans comprising tension members for supporting the opposite ends ofsaid concrete form, and selective power actuated means for lifting oneend or the other of said concrete form through said flexible means toeffect a predetermined distribution of concrete in the form undervibration.

3. In an apparatus for vibration of concrete, the combination of anelectric motor provided with an unbalancing weight adapted to be rotatedby the motor shaft, a resilient support for said motor, clamping memberscarried by the opposite ends of said resilient support and adapted toclamp a concrete form, and flexible means for suspending saidconcreteform, motor and support whereby said motor is adapted to place saidconcrete form in a state of high frequency vibration, said flexiblemeans comprising a plurality of tension members separately secured tospaced points on said support, and selective power actuated means forexerting force on any of said tension members whereby Various parts ofsaid form may be lifted and said form may be tilted into any of amultiplicity of different planes to effect a predetermined distributionof concrete in the form under vibration.

4. In an apparatus for high frequency vibration of concrete, thecombination of a concrete form having a laterally projecting securingflange at opposite sides of the form, with a framework comprising alongitudinally extending resilient metal member, clamping means at eachend of said framework for securing said member to the securing flange ofsaid form, and an electric motor vibrator having an eccentric weightcarried by the shaft of said motor, said vibrator being carried by saidresilient longitudinally extending member whereby said eccentric weightis adapted to place said concrete form in a state of vibration.

5. In an apparatus for high frequency vibration of concrete, thecombination of a concrete form having a laterally projecting securingflange at opposite sides of the form, with a framework comprising alongitudinally extending hanger clamping means at reach end of saidframework for securing said member to the securing flange of said form,and an electric motor vibrator having an eccentric weight carried by theshaft of flexible members for supporting said framework,

form and motor in a state of suspension whereby said concrete form maybe vibrated Without restraint.

6. fn an apparatus for Vibrating concrete, the combnationof a concreteform with a supporting framework, means for securing said framework tosaid" form, flexible means for suspending said framework from a supportfor free vibration without restraint, said framework comprising anelongated longitudinally extending resilient motor support, an electricmotor, and an eccentric Weight carried by the motor shaft, said motorbeing supported by said longitudinally extending resilient motor supportat the point of its greatest amplitude of vibration.

7. In an apparatus for vibrationg concrete, the

combination of a concrete form with a supporting framework, means forsecuring said framework to said form, flexible means for suspending saidframework from a support for freevibration without restraint, saidframework comprising an elongated longitudinally extending resilientmotor support, and a pair of electric motors, each having an eccentricweight carried by the motor shaft, said electric motors being carried bysaid longitudinally extending resilient member at points of maximumamplitude of vibration of said resilient member.

8. i In a-n apparatus for high frequency vibration of concrete, thecombination of a pair of longitudinally extending tracks with aframework having supporting and guiding rollers engaging saidtracks, andforming a longitudinally moving carriage with a transversely movingcarriage having` i supporting and guiding rollers engaging saidframework, said framework forming a transverse track, a motor having ahoist' drum carried by said carriage, a flexible member wound on saiddrum and depending therefrom, a 'plurality of diverging flexible memberscarried by said first- Vmentioned flexible member, said diverging exiblemembers supporting a concrete form, a resilient member secured to saidconcrete form, and an electric motor havin@r an eccentric weight carriedby said resilient member and adapted to place said concrete form in highfrequency vibration.

9. A method of treating concrete which comprises placing green concretein a mold, suspending the mold by fiexible tension members for freemovement, subjecting the mold to high frequency vibrations while sosuspended to improve the characteristics of the concrete and tilting themold by means of said tension members to control the eifect of saidvibrations and effect a more perfect filling of the mold. i i

JOHN W. LOWELL.

